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How Much Vitamin K is in...?

Find out the exact amount of Vitamin K (in micrograms) of almost a thousand
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of Vitamin K in the food, this list will help you know exactly how much Vitamin K you're eating. Just
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Ask Dr. Gourmet

Is it safe to eat cranberries while on Coumadin (warfarin)?

My husband went on Coumadin this week and one of the doctors told him, "NO cranberries." When we read how low the vitamin K is in cranberries, we questioned this.

The nurse researched it for us and was told that cranberries kill some
type of bacteria in your body and that the bacteria affects the
Coumadin. Is this correct?

Dr. Gourmet Says...

At the time there wasn't very good science investigating the issue of an interaction between cranberry juice and Coumadin (warfarin). The good news is that we now have pretty good evidence that it's OK to drink cranberry juice.

The feeling has been that somehow cranberry juice interacted with the
cytochrome P450 system of enzymes. These enzymes are critical
to helping the body clear itself of chemicals such as medications
we take. A group of researchers in Boston looked at whether cranberry
juice, brewed tea, grape juice or placebo would have an effect
on the specific P450 enzyme responsible for clearing warfarin
from the body. They used another drug, fluconazole, as a control
medication. (Clin Pharmacol Ther 2006;79:125–33.)

Guess what? No effect was seen on the clearance of medications in the
body by any of the test substances. Although there was some effect in the
test tube with grape juice and tea (not cranberry juice) this wasn't seen
when tested on humans.

In another study, a group had ten healthy volunteers drink cranberry
juice or water each day for ten days. They tested three different
drugs, including warfarin, to see if there was any difference
in the drug concentrations or the INR. Again, no difference. (Clin
Pharmacol Ther 2007;81:833–39.)

Those faithful readers who follow Dr. Gourmet know that I believe in
the importance of actual science before making claims. When it
comes to something like Coumadin, we were right to be cautious because
of the case reports. We now have evidence that it's OK for you to drink
cranberry juice (and eat cranberries) while taking warfarin.